This is your first fixed time mission, its not long- about 1:48 min! It is considered easy to average. Zoldiers, Knights and a new unit Boar Ridda will be coming after your convoy in set of groups from 1 to 3 units, from 2 to 4 groups at a time.
You arrive on the third land stripe at the middle bottom- this is your starting position! The enemy is over to the North- thats where he will spawn his "minions" to go after your trucks! If you loose all the trucks you loose the mission!
Notice, there is "Chichenitza" Wonder to the left of you, you can click it from some res if your storage allows it.
You start by focusing first! As the cut-scene closes- your trucks start moving and enemies running! What to do? Split up your army in groups! It is recommended to do it in 4 groups, but 2 will do fine also.
Don't bother counting that those allied turrets will ease your job! They may appear shooting the enemy, but they can't "lock on" the target nor they can deal enough damage to them! Sorry, but you are all alone in this one!
Send your first group to your (1.) bridge, your second to your (2.) and so on(* if you have more units). The Enemy will follow your trucks as they go by the blue line indicated in the screen-shot, Thus Orcs will be using their (1.) bridge, then (2.),(3.) and (4.)th.
You need to watch what bridges your enemy is using and where are your trucks, send your groups accordingly to your (1.-4.) bridges to meet them. Usually its a good idea to do this, when you notice your enemy starts to use a new bridge to cross over!
Finally as the last truck leaves the horizon, you have passed this stage! Your first tough one- no? At least you got yourself organizing your army, from now on we will call it micro-management! It is lots of clicking and organizing and you should be good at it!
See you on mission 4.!
** See a similar approach below!
* Experienced players may find using Air units to be a big help on this mission! Follow the yellow line charted in the screen-shot and move your Air units along the enemy paths! Hence- you can even do this on Air only! They will be able to sense coming enemy and engage them, if they do wonder of course, just pull them back on track and enjoy the show!
** Pro players might find this a little boring, sorry, you can't rush it! To make a challenge- try blowing up those spawn buildings- you won't destroy the actual spawn points- but you will get some credit for doing it! You can even send your groups to the middle land stripe or to spawn points directly- whether you want it- its up to you!